For her rainbow cake, I made six layers of white cake, dyed all different colors, and put vanilla pastry cream (what you put in the center of eclairs) between the layers. Then, I frosted the whole outside in chocolate frosting. I just did a couple of simple borders on it, and then it was time for fun. I made a batch of fondant and dyed it the different colors I would need to make Leia, an Ewok, and some trees to represent the forest of the moon of Endor. I shaped all the little characters, with my children watching in fascination, and then stuck them on the cake. I was very pleased with the result!
5 large egg whites and 1 whole egg, room temperature
8 fluid ounces whole milk
1 teaspoon pure vanilla extract
1/2 scraped vanilla bean
1/4 teaspoon almond extract
9 ounces unbleached all purpose flour
12 ounces granulated sugar
1 tablespoon baking powder
3/4 teaspoon salt
12 tablespoons unsalted butter, softened and cut into 12 pieces
purple, blue, green, yellow, orange, and red food dye
Heat oven to 350. Grease, line, and flour 3 eight inch cake pans. Weigh your mixing bowl and write down the weight. Place egg whites and egg, milk, vanilla, vanilla beans, and almond extract in a 2 cup measure and whisk together. Place flour, sugar, baking powder, and salt in mixing bowl. Mix dry ingredients with paddle attachment on low until combined. Add softened butter and beat on medium until butter pieces are smaller than peas. Increase speed to medium high and pour in all but 1/2 cup of the milk mixture. Let mix until smooth, 1 minute. Pour in remaining milk mixture and beat 1 more minute. Weigh the mixing bowl and batter and subtract out the weight of the bowl you wrote down earlier. Divide the remaining weight (the weight of the batter) by 6. Place small mixing bowls one at a time on the scale and add the correct amount of batter to each. Add food coloring to each bowl. Place 3 colors of batter into the pans and bake 10-15 minutes until a toothpick inserted in the center comes out clean. Cool in pans 10 minutes, then turn out onto wire racks, wash the pans, grease, line, and flour again and repeat with remaining batter. Cover cake layers with plastic wrap, and cool completely, 1 hour.